First-Level Instruction Cache Design for Reducing Dynamic Energy Consumption

Abstract

Microarchitects should consider energy consumption, together with performance, when designing instruction cache architecture, especially in embedded processors. This paper proposes a power-aware instruction cache architecture, named Partitioned Instruction Cache (PI-Cache), to reduce dynamic energy consumption in the instruction cache. The proposed PI-Cache is composed of several small sub-caches. When the PI-Cache is accessed, only one sub-cache is accessed by utilizing the locality of applications. In the meantime, the other sub-caches are not accessed, resulting in dynamic energy reduction. The PI-Cache also reduces energy consumption by eliminating energy consumed in tag matching. Moreover, performance loss is little, considering the physical cache access time. We evaluated the energy efficiency by running cycle accurate simulator, SimpleScalar, with power parameters obtained from CACTI. Simulation results show that the PI-Cache reduces dynamic energy consumption by 42% – 59%.